Lubricant compositions

ABSTRACT

Lubricant compositions are provided containing a corrosioninhibiting amount of an amine salt of the reaction product of at least one member of the group consisting of alkyl and alkenylsuccinic anhydrides and at least one member of the group consisting of benzotriazole and substituted benzotriazoles in a mole ratio of from 1:1 to 1:2.

United States Patent Davis et al.

[451 July 29, 1975 LUBRICANT COMPOSITIONS Inventors: Robert H. Davis, Pitman; John W.

Schick, Cherry Hill, both of NJ.

Assignee'. Mobil Oil Corporation, New York,

Filed: Oct. 4, 1973 Appl. No.: 403,692

US. Cl. 252/34; 252/493; 252/390;

260/308 B Int. Cl ClOm 1/32 Field of Search 252/34, 49.3, 390

References Cited UNlTED STATES PATENTS 6/1966 Davis 252/34 FOREIGN PATENTS OR APPLICATIONS 1,444,903 1 H1968 Germany Primary Examiner-Helen M. S. Sneed Attorney, Agent, or Firm-Charles A. Huggett; Raymond W. Barclay; Benjamin 1. Kaufman ABSTRACT 12 Claims, No Drawings l LUBRICANT COMPOSITIONS BACKGROUND OF THE INVENTION 1. Field of the Invention.

This invention relates to improved lubricant compositions and, in one of its aspects, relates more particularly to lubricant compositions that are normally susceptible of causing deterioration of metal surfaces with which they may come into contact or tend to undergo deterioration under conditions of use. Still more particularly, in this aspect, the invention relates to lubricant compositions in th form of lubricating oils, greases, or aqueous-base lubricants, which normally exhibit the aforementioned shortcomings in performing their intended functions.

2. Description of the Prior Art.

It is well known that certain types of lubricants, including lubricating oils, greases and aqueous-base cutting fluids are susceptible of causing deterioration by oxidation or corrosion when coming into contact with various metal surfaces. In addition, such lubricants may also tend to undergo deterioration in performing their intended functions, for example, in the impairment of load-carrying characteristics, thus clearly indicating the necessity for incorporating in such lubricants effective anti-oxidative and corrosion inhibiting improving agents.

Of particular significance, is the machining operations of metals, such as cutting, grinding, turning, milling and the like where it is customary to flood the tool and the work with a coolant for the purpose of carrying off heat which is produced during the operation. It is also customary to employ these coolants in combination with various agents having lubricating and extreme-pressure properties for reducing friction between the tool and work-piece, particularly in operations such as tapping and broaching. In this respect, it has heretofore been the practice to employ for such purpose aqueous compositions containing such lubricating agents as emulsified petroleum or nonpetroleum additives. In order for such aqueous cutting fluids to perform satisfactorily, is the requirement that residual deposits on the tool and the work following the machining operation are avoided. Other important requirements include tolerance in hard water solutions so that precipitation of lubricant components will not occur and that tacky residues which interfere with the operation of the machine, as well as excessive foam formation are avoided. Cutting fluids, known prior to the present invention, have not, however, satisfactorily met the foregoing requirements.

SUMMARY OF THE INVENTION It has now been found that the aforementioned corrosion and oxidative inhibiting properties can be effectively improved by incorporating, in minor proportion corrosion-inhibiting amounts of an amine salt of the re action product of at least one member of the group consisting of alkyl and alkenylsuccinic anhydrides and at least one member of the group consisting of benzotriazole and substituted benzotriazoles, in a mole ratio of from 1:1 to 1:2. For most applications, these amine salts are employed in an amount of from about 0.001 to about 40%, and preferably, in an amount from about 0.5 to about 10%, by weight, of the total lubricant composition. Preferably, the amine and the aforementioned reaction product are reacted in a mole ratio of about 1:1.

Where the lubricant comprises an oil of lubricating viscosity, the lubricant may comprise many mineral or synthetic oils of lubricating viscosity. In instances where high temperature stability is not a prime requirement, mineral oil at a viscosity of at least 40 SSU at l00F. and particularly those falling within the range from about 60 SSU to about 6000 SSU at F. is preferably employed. In instances where the lubricant comprises a synthetic hydrocarbon oil rather than a mineral oil, or in combination therewith, various compounds of this type may be successfully utilized. Typical synthetic vehicles include: polypropylene glycol, trimethylol propane esters, neopentyl and pentaerythritol esters, di-(2-ethyl hexyl) sebacate, di-(Z-ethyl hexyl) adipate, dibutyl phthalate, fluorocarbons, silicate esters, silanes, esters of phosphorous-containing acids, liquid ureas, ferrocene derivatives, hydrogenated mineral oils, chain-type polyphenyls, siloxanes and silicones (polysilioxanes), alkyl-substituted diphenyl ethers typified by a butyl-substituted bis (p-phenoxy phenyl) ether, phenoxy phenyl ethers, etc.

The aforementioned liquid hydrocarbon lubricants may also be employed in combination with a grease forming quantity of a thickening agent as vehicles in the production of greases containing the abovedescribed amine salts. For this purpose, a wide variety of materials may be employed. These thickening or gelling agents may include any of the conventional metal salts or soaps, which are dispersed in the lubricating vehicle in grease-forming quantities, in such degree as to impart to the resulting grease composition, the desired consistency. Other thickening agents that may be employed in the grease formation may comprise the nonsoap thickeners, such as surface-modified clays and silicas, aryl ureas, calcium complexes and similar materials. In general, grease thickeners may be employed which do not melt and dissolve when used at the required temperature within a particular environment; however, in all other respects, any material which is normally employed for thickening or gelling hydrocarbon fluids for forming grease can be used in preparing the aforementioned improved grease in accordance with the present invention.

Any amine may be employed for forming the salt of the aforementioned reaction product of at least one member of the group consisting of alkyl and alkenylsuccinic anhydrides and at least one member of the group consisting of benzotriazole and substituted benzotriazoles. In a preferred modification alkanolamines are most advantageously employed and may be of any molecular weight. Preferably these amines should be liquid at room temperature. The lower molecular weight amines are generally preferred and for this purpose, it has been found that such alkanolamines as mono-, dior tri-ethanolamine are most effective. The amines may be water soluble or oil soluble and may,

therefore, include such alkanolamines as isopropanolamines, e.g. mono-, diand triisopropanolamine, di-methylethanolamine, diethylethanolamine, aminoethylethanolamine, N-acetyl ethanolamine, phenylethanolamine, phenyldiethanolamine, and mixtures thereof.

Any alkyl or alkenylsuccinic anhydride may be employed for reaction with benzotriazole or substituted benzotriazoles in producing the aforementioned reacbenzotriazole reaction product, the junction corrosion test results dropped to 62 microamps, as shown in Example 4, and indicating that this additive system is considered satisfactory for machining a nonferrous metal such as magnesium without corrosion problems associated with steel contact on the machine tool.

Table Aqueous Coolant Galvanic Corrosion Inhibitors Tctrapropcnyl Galvanic Corrosion Test Tetrasuccinic Microamps for Magncsium/ propcnyl Anhydridc/ Steel Couple (Test soln. Triethanolsuccinic Bcnzo- Benzotriazole 40 parts dist. water. Example amine Anhydride triazolc Reaction Product Water I part additive concentrate) hydride and isooctadecylsuccinic anhydride. Typically representative of the substituted benzotriazoles is tolyl triazole. It should also be noted that in addition to imparting corrosion-inhibiting properties to lubricant compositions, the amine salts of the present invention are also effective in imparting anti-wear, anti-rust and bactericidal properties thereto.

DESCRIPTION OF SPECIFIC EMBODIMENTS The following examples and comparative data will serve to illustrate the amine salts of the present invention and to demonstrate their effectiveness in lubricant compositions which are normally susceptible of causing oxidative and corrosive deterioration of metal surfaces with which they may come into contact or tend to undergo deterioration under conditions of use, and particularly with respect to the use of these amine salts in Inbricating oils, greases and water-base lubricants. It will be understood, of course, that it is not intended the invention be limited to the particular compositions disclosed or to the operations or manipulations involved. Various modifications thereof can be employed and will be readily apparent to those skilled in the art.

A series of additive systems were evaluated, as shown in the following table, in accordance with a well-known galvanic corrosion test which provides for a bimetallic magnesium/steel couple separated by a glass cloth strip and shorted with a three inch wire. This couple is immersed in a 40/1 test lubricant-coolant solution. After 24 hours, the shorted wire is replaced with microammeter leads and current is measured. Values in excess of 120 microamps are indicative of severe corrosion and cause for lubricant rejection.

As will be seen from the comparative data of the table typical formulations considered unsatisfactory for nonferrous metal machining are represented by examples l, 2 and 3. In example 1 there is employed a 43%, by weight, aqueous triethanolamine solution, which is found to stain magnesium and results in a 295 microamp current reading. If an amine is combined to form a salt of benzotriazole and tetrapropenylsuccinic acid, respectively, in examples 2 and 3, the current values still exceed 120 microamps. However, if triethanolamine is combined with a tetrapropenylsuccinic acid/- It will be understood that although the present invention has been described with preferred embodiments, various modifications and adaptations thereof may be resorted to without departing from the spirit of the invention as those skilled in the art will readily understand.

We claim:

1. A lubricant composition containing a corrosioninhibiting amount of an alkanolamine salt of the reaction product of at least one member of the group consisting of alkyl and alkenylsuccinic anhydrides and at least one member of the group consisting of benzotriazole and tolyl triazole in a mole ratio of from 1:1 to 1:2.

2. A composition in accordance with claim 1 wherein said lubricant comprises an oil of lubricating viscosity.

3. A composition in accordance with claim 1 wherein said lubricant comprises a grease.

4. A composition in accordance with claim 1 wherein said lubricant comprises water in major proportion.

S. A composition in accordance with claim 1 wherein said alkanolamine salt is present in an amount from about .001 to about 40%, by weight.

6. A composition in accordance with claim 1 wherein said alkanolamine salt is present in an amount from about 0.5 to about 10%, by weight.

7. A composition in accordance with claim 1 wherein said alkanolamine and said reaction product are reacted in a mole ratio of about 1:1.

8. A composition in accordance with claim 1 wherein the alkanolamine is tri-ethanolamine.

9. A composition in accordance with claim 1 wherein the alkenylsuccinic anhydride is octenylsuccinic anhydride.

10. A composition in accordance with claim 1 wherein the alkenylsuccinic anhydride is polybutenylsuccinic anhydride.

11. A composition in accordance with claim 1 wherein the alkenylsuecinic anhydride is triacontenylsuccinic anhydride.

12. A composition in accordance with claim 1 wherein the alkenylsuccinic anhydride is isooctadecylsuccinic anhyride. 

1. A LUBRICANT COMPOSITION CONTAINING A CORROSION-INHIBITING AMOUNG OF AN ALKANOLAMINE SALT OF THE REACTION PRODUCT OF AT LEAST ONE MEMBER OF TE GROUPCONSISTING OF ALKYL AND ALKENYLSUCCINIC ANHYDRIDES AND AT LEAST ONE MEMBER OF THE GROUP CONSISTING OF BENZOTRIAZOLE AND TOLYL TRIAZOLE IN A MOLE RATIO OF FROM 1:1 TO 1:2.
 2. A composition in accordance with claim 1 wheRein said lubricant comprises an oil of lubricating viscosity.
 3. A composition in accordance with claim 1 wherein said lubricant comprises a grease.
 4. A composition in accordance with claim 1 wherein said lubricant comprises water in major proportion.
 5. A composition in accordance with claim 1 wherein said alkanolamine salt is present in an amount from about .001 to about 40%, by weight.
 6. A composition in accordance with claim 1 wherein said alkanolamine salt is present in an amount from about 0.5 to about 10%, by weight.
 7. A composition in accordance with claim 1 wherein said alkanolamine and said reaction product are reacted in a mole ratio of about 1:1.
 8. A composition in accordance with claim 1 wherein the alkanolamine is tri-ethanolamine.
 9. A composition in accordance with claim 1 wherein the alkenylsuccinic anhydride is octenylsuccinic anhydride.
 10. A composition in accordance with claim 1 wherein the alkenylsuccinic anhydride is polybutenylsuccinic anhydride.
 11. A composition in accordance with claim 1 wherein the alkenylsuccinic anhydride is triacontenylsuccinic anhydride.
 12. A composition in accordance with claim 1 wherein the alkenylsuccinic anhydride is isooctadecylsuccinic anhyride. 